Rotary engines

ABSTRACT

A rotary engine having a housing with a four-lobed cavity therein and a three-lobed rotor disposed in the cavity, the cavity and the rotor having cooperating surfaces all of which are sections of right circular cylinders and in which the rotor moves within the cavity by sequential pivotal movement of the rotor about its lobe apexes in the corner lobe edges of the cavity. A drive shaft coaxial with the cavity is coupled to the rotor by means allowing the rotor axis to move towards and away from the axis of the cavity as the rotor rotates within the cavity.

United States Patent [191 McCullough et al.

1 Nov. 25, 1975 1 ROTARY ENGINES Filed: July 30, 1973 [21] Appl. No.: 384,071

Wanzenberg et al7 418/61 B Lcroy et a1 418/61 B Primary E.\'aminer-William L. Freeh Assistant EraminerLeonard Smith Attorney. Agent, or Firn1Phillips, Moore, Weissenberger, Lempio & Strabala [57] ABSTRACT A rotary engine having a housing with a four-lobed cavity therein and a three-lobed rotor disposed in the cavity, the cavity and the rotor having cooperating surfaces all of which are sections of right circular cylinders and in which the rotor moves within the cavity by sequential pivotal movement of the rotor about its lobe apexes in the corner lobe edges of the cavity. A drive shaft coaxial with the cavity is coupled to the rotor by means allowing the rotor axis to move towards and away from the axis of the cavity as the rotor rotates within the cavity.

20 Claims, 22 Drawing Figures US. Patent Nov.25, 1975 Sheetlof6 3,922,120

US. Patent N0v.25, 1975 Sheet2of6 3,922,120

US. Patent Nov. 25, 1975 Sheet 3 of6 US. Patent Nov. 25, 1975 Sheet40f6 3,922,120

US. Patent Nov.25, 1975 Sheet6of6 3,922,120

ROTARY ENGINES BACKGROUND OF THE INVENTION This invention relates to rotary engines having a lobed cavity in which a rotor is arranged to travel unidirectionally in the cavity, as opposed to the bidirectional movement of a reciprocating piston engine, the rotor forming with the cavity a plurality of expansible chambers in which compression and expansion take place as the rotor travels through the cavity.

Present engines of this type have two significant drawbacks. One, the shapes of the cavity and rotor are made up of complex curves which are expensive to machine and difficult to repair. Secondly, in such engines it is necessary to maintain the rotor apexes in constant engagement with the peripheral wall of the cavity so that leakage past therebetween will not occur as the chambers expand and contract through the interaction of the rotor and the cavity walls. Attempts have been made to overcome this latter problem by providing seals on the rotor apexes which move relative to the rotor to maintain the desired seal. However, moving parts are difficult to maintain as operational, particularly if the engine is used as an internal combustion engine.

Further, such engines have been designed to produce only one or two power strokes per revolution of the drive shaft relative to the housing, which limits the amount of power obtainable from a given size engine.

SUMMARY OF THE INVENTION The present invention provides a rotary engine in which the housing cavity and rotor each have a particular shape, made up of plane surfaces and arcuate surfaces which are segments of right circular cylinders, all of which surfaces are easy to machine and maintain.

With the particular shapes of the rotor and cavityof the present invention, the rotor is confined within the cavity so that the rotor sequentially pivots about one of its three apexes in one of the cavity lobe corners. The sequential pivotal movement of the rotor in the cavity causes the axis of the rotor to travel around the cavity in a path offset from the axis of the cavity, the axis of the rotor moving towards and away from the cavity axis as the rotor axis travels around the cavity. A drive shaft coaxial with the cavity is coupled to an axial drive stub on the rotor so that the path of movement of the rotor stub around the cavity drives the drive shaft relative to the housing, the rotor and drive shaft being coupled together so as to allow the rotor stub to move freely towards and away from the axis of the cavity.

Because of the particular geometry of the rotor and cavity, as the rotor pivots about any of its three lobe apexes, the other two rotor lobe apexes wipe along the cavity walls facing the cavity corner in which the axis of pivotal movement lies. Thus, at all times, all three rotor apexes engage and seal against the peripheral wall of the cavity.

The present engine, as described in fuller detail hereinafter, can be used as an internal combustion engine, a pump or a fluid-powered motor.

When used as an internal combustion engine, the engine can be operated so as to provide four power strokes, one from firing of fuel in each of the four cavity lobes, for each revolution of the drive shaft. Two engines can be coupled together easily, and offset from 2 each other to provide the equivalent of an eight-cylinder engine.

Another important aspect of the present invention is that the intake and exhaust into each cavity lobe can take place through longitudinal passages through the drive shaft. Valving of these passages can be by wiping action of the rotor across the end of the shaft through which the passages extend, or such shaft passages can communicate with passages in the end wall of the housing through which the shaft extends, with valving of the passages being accomplished by bringing the passages in the shaft and end wall into and out of registration with each other as the shaft rotates.

A significant advantage of the use of the passages through the shaft is that external manifolds on the housing for intake and exhaust can be eliminated and the housing, symmetrical about its axis, can be rotated relative to the drive shaft so that the drive shaft may be held stationary and the power output can be taken off of the rotating housing.

Other objects and advantages of the present invention will become apparent in the course of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings forming apart of this application,

FIG. 1 is a perspective view of the main housing member of the engine;

FIG. 2 is a perspective view of one of the two end walls of the housing;

FIG. 3 is a perspective view of the drive shaft;

FIG. 4 is a perspective view of the rotor;

FIGS. 5 and 6 are geometrical diagrams illustrating the manner in which the outlines of the housing cavity and rotor are generated;

FIG. 7 is a sectional view of the housing, looking into the cavity thereof, with the shaft in place but with the rotor removed;

FIG. 8 is a view similar to FIG. 7, showing the rotor in place within the housing cavity;

FIG. 9 is a sectional view of a modification of the engine, arranged as an air-cooled internal combustion engine;

FIG. 10 is an elevational view of the engine of FIG. 9, mounted on a frame for power take-off from either or both the housing and shaft;

FIG. 11 is a sectional view of a modification of the housing, illustrating an alternative manner of providing intake and exhaust passages from the cavity lobes to and through the shaft;

FIG. 12 is a sectional view of the housing and shaft, taken on line 12l2 of FIG. 11;

FIG. 13 is a sectional detail of the engine illustrating another modification of the inlet and exhaust means;

FIG. 14 is a sectional transverse view of the housing, with the rotor shown in dotted lines for purposes of illustration, illustrating a modification of the drive shaft and rotor;

FIG. 15 is a sectional view, taken on line 15l5 of FIG. 14;

FIG. 16 is a generally schematic view, with the rotors omitted for purposes of illustration, of two engines coupled together and arranged for serial flow of fluid from one engine to the other;

FIG. 17 is a generally schematic view, with the rotors omitted for purposes of illustration, of two engines coupled together and independently powered;

FIG. 18 is a generally schematic view, with the rotors omitted for purposes of illustration, of another manner in which two engines may be coupled together;

FIG. 19 illustrates in schematic form a modification of the invention arranged as a fluid pump;

FIG. 20 illustrates, in schematic form, another modification of the invention arranged as a fluid-operated motor;

FIGS. 21A through L illustrate diagrammatically the sequence of movements of the rotor within the housing during a complete revolution of the shaft relative to the housing;

FIG. 22 illustrates a modification of the invention arranged to operate as a four-cycle internal combustion engine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1-4 show the basic components of the rotary engine of the present invention. The housing comprises a main block 11 and two end members 12. Block 1 1 has an inner peripheral wall 13 forming a four-lobed cavity of constant cross section along and symmetrical with the axis of the cavity. If desired, longitudinal passages 14 may be provided through the block adjacent the peripheral wall 13 for cooling purposes. Tapped holes 15 are provided at appropriate points into both ends of the block for assembly of the end members thereto. The outer peripheral wall 16 of the block is shown in FIG. 1 as square in axial cross section, but such shape may be of any desired configuration, such as cylindrical.

End member 12 (FIG. 2) has an exterior peripheral surface 17 of the same shape as that of block 11, and a flat inner wall 18 which forms one end wall of the housing cavity. Cooling recesses 19 may be formed into wall 18 of the same shape as block passages 14, and coolant conduits 20 are provided for external communication with each cooling recess 19. Bolt holes 21 are provided through the end member 12 for registration with the tapped holes 15 in block 11. A central opening 22 is provided through end member 12 to accommodate shaft 25 therein. The opposite end member 12 is to accommodate shaft 25 therein. The opposite end member 12 is similarly formed, but may or may not have a shaft opening 22 therethrough, depending upon whether a shaft 25 is desired at that end of the housing.

Shaft 25 (FIG. 3) is circular in cross section and sized to fit within end member opening 22 and project outwardly therefrom. End member 12 is provided with a conventional sealed bearing (not shown) to journal shaft 25 for rotation in the housing. A circular head 26 formed on the end of shaft 25 and axially offset relative thereto is provided with a slot 27 which extends radially of the shaft. Two arcuately shaped passages 28 and 29 are formed longitudinally through the shaft when it is desired to use the shaft for intake and exhaust, as will be explained hereafter. Passages 28 and 29 open out radially, at 30 and 31 respectively, through the other end of shaft 25 for connection to intake and exhaust conduits.

The symmetrical three-lobed rotor 35 (FIG. 4) has an overall length equal to the length of the housing cavity, and is of constant cross section throughout its length. When the rotor is to be used in an internal combustion engine, a compression depression 36 is formed into the surface of one wall of each lobe of the rotorr. A recess 37 is formed into the end wall 38 of the rotor,

recess 37 being circular in shape with the axis thereof being coaxial to the axis of the rotor and being sufficiently large in diameter to provide clearance for the offset head 26 of shaft 25. A drive stub 39, of circular section, is formed integrally with rotor 35 and coaxial therewith, the stub being of a diameter to fit within the radial slot 27 of shaft 25. The end wall 38 also has three arcuate wiper elements 40 inserted into the end wall of the rotor and extending outwardly therefrom, each wiper 40 extending between two of the apexes of the rotor, the wipers 40 being utilized to provide a wiping seal of the end of the rotor to the end wall 18 of the cavity. Both ends of the rotor are provided with such wipers 40. If a drive shaft 25 is to be provided through each end member 12, then the rotor 35 will be provided with an axial recess 37 and drive stub 39 at both ends thereof.

FIG. 5 illustrates the generation of the cross-sectional shape of the four-lobed block cavity. A square ABCD is constructed of the size desired. From each corner of the square an arc of a circle of radius r is drawn, the radius of the are being equal to the length of a side of the square ABCD. For example, with the corner A as a center, the arc BFGD will be constructed. The desired cavity is defined by the solid-lined envelope AEBFCGDI-IA of the constructed arcs. As is seen, each corner of the cavity, e.g., corner A, has two cavity walls facing that corner, e.g., BF and GD, which lie on a circle having that corner as a center. When the block 11 has a constant cross-section cavity formed therethrough, FIG. 1, the cavity will have four corner edges, e.g., D-D, and eight lobe wall surfaces, e.g., DD- GG, each wall surface being a section of a circular cylinder whose axis is along the corner edge towards which the wall surface faces and whose radius is equal to the distance between adjacent corner edges, e.g., the radius of wall D-D'-G'-G is equal to the distance between corner edges D and A.

FIG. 6 illustrates the generation of the cross-sectional shape of rotor 35. An equilateral triangle UK is first constructed, each side of the triangle being substantially equal in length to the side of the square ABCD used to determine the block cavity, but slightly less to provide the necessary clearance between the rotor and the cavity as the rotor moves within the cavity. From each side of the triangle UK, a square is constructed, with the triangle IJ K lying therewithin, e.g., square ILMK. From each outside corner of the three constructed squares, i.e., points L, M, N, O, P and Q, an arc is constructed, with a radius r equal to the length of the side of the square. The solid-line envelope of arcs IRJSKTI is the desired cross-sectional shape of the rotor 35. Thus, arcs IR and R] are both segments of a circle. correspondingly, the walls IIR'R and RR'J'J of rotor 35 are segments of right circular cylinders. As is seen, the lower arcuate surfaces KTI of the rotor is complementary to the lower arcuate walls DI-IA of the cavity. Also, the distance between adjacent rotor apexes, e.g., I] is equal to the distance from cavity corner A to the cavity wall BF.

In summary, each cavity wall and each rotor wall is a section of a right circular cylinder, all sections having the same curvature of radius, with allowance for clearance to permit movement of the rotor within the cavity. The end wipers 40 are also segments of circles, the circles being defined by three points, namely, two rotor apexes and a point therebetween which is spaced radially outward from the end cavity 37. Thus, the block and rotor may be machined far more easily than if complex curves were involved.

FIG. 7 illustrates in simplified form the manner in which the engine is assembled, showing the end member 12 secured to block 11 with the end wall 18 facing into the cavity, and with the shaft 25 in place with the end of the shaft being flush with cavity wall 18 and with the offset head 26 projecting into the cavity. FIG. 8 shows the addition of rotor 35, with the offset shaft head 26 received within rotor recess 37 and with the rotor drive stub 39 received within the slot 27 of the offset shaft head 26.

FIG. 9 shows a rotary engine constructed in accordance with the present invention and arranged for operation as an aircooled internal combustion engine. In the form shown herein the main block 11a has an inner peripheral wall 13, shaped as previously described and an outer peripheral wall 163 generally parallel to the inner wall 13, the outer wall having radially extending cooling fins 51 thereon. The block has four openings 52 therethrough, one for each lobe of the cavity, into which spark plugs 53 are mounted. Rotor 35 and shaft 25, as previously described, are disposed in the housing, rotor 35 having a compression depression 36 in one face of each lobe thereof.

The operation of an engine as an internal combustion engine can best be described by reference to FIGS. 21A-L, which show the sequence of operations for one complete revolution of shaft 25 relative to housing 10. In these figures the housing is stationary, shaft 25 is rotating in a clockwise direction and rotor 35 is turning in a counterclockwise direction.

FIG. 21A shows the rotor 35 within the block cavity in a position after rotor faces KTI have moved down against cavity faces DI-IA to compress fuel into the compression depression 36 in rotor face TI. at this time rotor 35, which wipes across the end of shaft 25, exposes the inlet opening 28 in shaft 25 to the left cavity portion bounded by cavity walls FCGD and rotor faces JSK, and a fuel mixture from an injection system is being charged into that cavity portion. Simila ly, the right cavity portion bounded by cavity walls AEBF and rotor faces JRI is exposed to the exhaust opening 29 in the shaft so that combustion products from a previous firing may be expelled from that cavity portion. At this point in the cycle, spark plug 53A is tired to ignite the fuel mixture.

Ignition of the fuel causes it to expand, forcing rotor 35 to pivot in a counterclockwise direction about its apex K which bears against cavity corner edge D. During this movement, rotor apex I wipes along cavity wall AE so that the expanding gases cannot escape therepast. This pivotal movement of rotor 35 causes the drive stub 39 thereof to travel upwardly and to the left in an arc whose center is rotor apex K, which in turn drives against the slot 27 in drive shaft head 26 to force the shaft to turn in a clockwise direction.

When the rotor reaches the position shown in FIG. 21B, the rotor and shaft have turned far enough relative to each other so that the rotor wipes across the end face of the drive shaft to close off the intake passage 28 from the left cavity portion. The right cavity portion continues to exhaust through shaft passage 29.

Continued expansion of the ignited fuel moves the rotor, and drives the shaft, to the position shown in FIG. 21C. As the rotor pivots about its apex K, its apex J wipes along cavity wall CF and compresses the fuel mixture in the left cavity portion. The relative move- 6 ment of the rotor and shaft causes the rotor to begin closing off the exhaust passage from the upper right cavity portion and to begin opening the intake passage to that cavity portion.

As shown in FIG. 21D, expansion continues in the lower right cavity portion and compression continues in the left cavity portion. The exhaust passage from the upper right cavity portion is almost closed and the intake passage thereinto is almost fully open.

When the rotor and shaft reach the position shown in FIG. 2115) the exhaust passage is fully closed by the rotor and the intake passage is fully open to the upper right cavity portion.

FIG. 21F shows the rotor as having pivoted fully about its apex J so that the rotor faces JSK lie against the cavity faces CGD, with the fuel mixture therebetween being compressed into the compression depression 36. This depression is sized, relative to the initial volume of the cavity portion into which fuel has been injected, so as to provide the desired compression ratio. At this point in time the rotor uncovers the exhaust passage so that the lower right cavity portion can begin to exhaust the products of combustion therefrom. Fuel inlet continues into the upper right cavity portion.

During the portion of the cycle just described one ignition and expansion and one fuel compression has taken place. The rotor has pivoted about its apex K through an arc of 30 and the shaft has been driven a quarter turn. As the rotor pivoted about its apex K, the axial drive stub 39 thereof rode up in drive shaft slot 27 towards the center of the housing, to the limit position shown in FIG. 21C and then rode outwardly in the slot as the rotor continues to pivot, to the limit position shown in FIG. 21F. Thus, the rotor stub turns with the rotor and rides in and out of the slot 27 towards and away from the axis of the cavity as the engine operates.

During this time the volume of the cavity portion exposed to rotor faces IRJ remain essentially constant and exhaust and intake occur from and into that cavity portion for the whole of the described cycle portion. As a result, although the sequence of operations is essentially that of a two-cycle engine, the volumetric efficiency of exhaust and intake is substantially greater than a two-cycle reciprocating piston engine.

When in the position shown in FIG. 21F the next spark plug 53B is tired to ignite the compressed fuel mixture. Expansion of the fuel now causes rotor 35 to pivot in the cavity about its apex J which now bears against cavity corner edge C, as shown in FIG. 21G. Expansion, compression, exhaust and intake in the three cavity portions take place as previously described. This portion of the cycle continues until the elements reach the position shown in FIG. 21H. At this time, the next spark plug 53C is ignited and rotor 35 is pivoted about its apex I, through the position shown in FIG. 21! to the position shown in FIG. 21.]. The next spark plug 53D is ignited, pivoting rotor 35 about its apex K through the position of FIG. 21K to the position shown in FIG. 21]...

During the full cycle shown in FIGS. 21A through 21L, four firings have taken place, the rotor has pivoted about its axis four times so that the rotor has rotated about its axis in the housing and the shaft has been driven through a full 360 revolution. Because of the geometry of the cavity and rotor, all three apexes of the rotor have been in continued contact with the walls of the cavity. Thus, no complicated wiper elements having moving parts are required to prevent flow past the rotor apexes.

7 As may be appreciated from FIGS. 21A-L, since the housing 10 is symmetrical and since intake and exhaust takes place through the shaft, it is quite feasible to hold the shaft stationary and allow the movement of the rotor (produced by the ignition of the fuel) to drive the housing. For example, if the elements are in the position shown in FIG. 21A and spark plug 53A is ignited, the rotor will again pivot about its apex K in the cavity corner edge D. Since the rotor drive stub 39 is now confined to up-and-down movement (as viewed in the drawings) in the shaft slot 27, movement of rotor face IT away from cavity wall Al-I will cause the rotor to rotate about its axis in a counterclockwise direction which causes its apex K to apply a force thereat to drive the housing in a counterclockwise direction. In the time required for one firing sequence, i.e., corresponding to the sequence shown in FIGS. 21A-F, the rotor will rotate 120 counterclockwise to the shaft, the rotor will rotate 30 counterclockwise relative to the housing and the housing will rotate 90 counterclockwise relative to the shaft, all of which is the same degree of relative movement as when the housing is held stationary and the shaft is allowed to turn.

FIG. 10 illustrates an arrangement wherein either or both the housing and the shaft may be used for power take-off. The housing 10a is provided with shafts and 25a at both ends thereof, the shafts being rotatably supported in roller journals 61 fixed to frame 62. Shaft 25a is either provided without passages therethrough or else such passages are plugged. The shaft 25 is journaled in and extends through a fixed double-chambered manifold 63 which provides communication with the intake and exhaust ports 31 and through the side of the shaft, so that fuel from a suitable fuel injector (not shown) may be delivered to the intake passage and exhaust gases may be delivered to a muffler or other exhaust system. A conventional ignition system is provided, and may be in the form of a magneto 64 fixed to housing 10a and timed by a cam (not shown) on shaft 25, to fire the spark plugs 53 at the proper time. A drive gear 65, fixed to drive shaft 25, is in mesh with power take-off gear 66. Another drive gear 67 surrounds and is fixed to housing 10a and is in mesh with power takeoff gear 68.

With this arrangement, gear 68 can be held stationary relative to frame 62, which in turn will hold housing 10a stationary relative to frame 62. In such case, operation of the engine will drive the shaft 25 relative to frame 62 for power take-off from gears 65 and 66. Conversely, if gear 66 is held stationary, operation of the engine will provide power take-off from gears 67 and 68. If the drive shafts of both gears 66 and 68 are connected to variable load devices, e.g., the drive wheels of a vehicle, a differential operation is obtained wherein for a given speed of rotation of the housing relative to the shaft, a reduction in speed of rotation of gear 66 relative to frame 62 will result in a corresponding increase in speed of rotation of gear 68, and vice versa.

FIGS. 11 and 12 illustrate another modification of the engine for providing a different manner of intake and exhaust through the drive shaft. Block 11b is formed with a four-lobed cavity as previously described. Intake passages 71 are provided, one for each cavity lobe, from each lobe through 11b, to registering passages 72 in end member 12b, which passages open to elongated grooves 73 in the periphery of the shaft opening 22b. Shaft 25b has an intake passage 28b therein which opens through the side of the shaft through port 74.

Similarly, exhaust passages 76 in block 11b communicate each cavity lobe to passages 77 and gears 78 in end member 12b, and thus to the exhaust ports 79 of the exhaust passage 29b through shaft 25b.

As shaft 25b rotates, the intake and exhaust ports 74 and 79 thereof will open to each of the four intake and exhaust passages in end member 12b in sequence during each full revolution of the shaft. The peripheral length of the grooves 73 and 78 and the radial location of the intake and exhaust ports on the shaft relative to the radial location of the shaft head slot 27 are chosen to provide the sequence of operations described in connection with FIGS. 21A-L.

FIG. 13 illustrates another manner in which intake into and exhaust from the four lobes of the cavity may be accomplished. In this modification block 11c is provided with a passage 81 through the peripheral wall thereof which communicates a cavity lobe with intake manifold 82. Intake valve 83 is disposed in passage 81 and is biased to closed position against valve seat 84 by spring 85. Push rod 86 is arranged to be driven downwardly, as viewed in FIG. 13, once for each revolution of drive shaft 250 by cam lobe 87 on the drive shaft. Such movement actuates rocker arm 88 to force valve 83 to open position against the bias of spring so that fuel in intake manifold 82 can be injected into the cavity lobe.

Each cavity lobe will have a similar valved inlet through the peripheral wall in communication with intake manifold 82, so that each lobe will be sequentially charged with fuel during one revolution of the drive shaft.

Similarly, each cavity lobe will have an exhaust passage therefrom through the peripheral wall to an exhaust manifold, the exhaust passages being valved in the same way and opened sequentially by a cam on the drive shaft.

In this modification all intake and exhaust from the cavity lobes takes place through the peripheral wall of the block and none takes place through the drive shaft. However, by suitable design and radial location of the intake and exhaust cams on the drive shaft the same sequence of operation as described in FIGS. 21A-L will be obtained.

FIGS. 14 and 15 illustrate another modification of the basic engine. In this modification, the main block 11d is the same as previously described. End member 12d is modified in that the shaft opening 22d has a radially enlarged portion 91 opening into the cavity. Shaft 25d has a radially enlarged flange 92 on the end thereof fitting into the shaft opening 91 but not extending into the cavity. A radial slot 27d is formed into the face 93 on the shaft flange 92. Rotor 35d does not have an axial recess 37 formed into the end wall thereof as before, but instead the axial drive stub 39d thereon projects beyond the end face of the rotor and is received in shaft slot 27d. Drive shaft 25d may be provided with intake and exhaust passages 28 and 29 therethrough if intake and exhaust is desired through the shaft.

FIG. 16 illustrates in simplified form the manner in which two engines 10e and 10f may be coupled together for serial flow of fluid therethrough. For ease in illustration the rotors are not shown. However, the rotor in engine 10c will have axial drive stubs on both ends thereof disposed in the radial slots 27e of shafts 25e and 25ef, and the rotor in engine l0fwill have axial drive stubs on both ends thereof disposed in the radial slots 27f of shafts 25ef and 25f. Preferably the rotors are offset from each other to provide for better balance of the coupled engines.

Shaft 25e has an intake passage 28e therethrough so that each lobe can have fuel injected thereinto, in the same manner as previously described. Exhaust from the cavity lobes of engine 102 takes place as before, but through the exhaust passage 29s in the opposite shaft 25ef. Exhaust passage 29e opens into the intake passage 28e in shaft 25efso that the exhaust gases from engine 10e are the intake gases in engine 10f. Engine 10f then exhausts through exhaust passage 29fin shaft 25f.

With this arrangement a rich fuel mixture can be injected into engine 10e and ignited with the combustion products then being injected into engine lffor recompression and reignition so that more completely combusted vapors will be exhausted from engine f. The fuel mixture in engine 10f will be leaner and the operating temperature will be lower for better emission control from engine 10f. If desiredjan intake manifold 95 may be provided around shaft efso that chemical additives and/or additional fuel may be injected through shaft ports 96 into engine 10f, if desired.

FIG. 17 shows an arrangement wherein two engines 10g and 10h may be coupled together with a solid drive shaft 25gh extending into the cavities of both engines. Intake and exhaust into both engines is separate, although a common intake manifold can be used to supply both engines with fuel from a single supply, and both engines can exhaust into a common exhaust manifold. Coupling of the two engines together will produce twice the power output. If desired, one or more additional engines may be coupled to engines 10g and 10h to increase the power output.

FIG. 18 is another arrangement showing two engines l0j and 10k coupled together, with shafts 25j and 25k connected together by an adjustment collar 98. By means collar 98 shafts 25jand 25k can be rotationally adjusted relative to each other so that the shaft slots 27j and 27k are radially offset from each other by an odd multiple of 45. As a result, with both engines in operation, the drive shafts will be power-driven alternately by. the engines once for every 45 of rotation of the shafts relative to the housings.

If desired the engine of the present invention can be arranged to operate as a-four-cycle engine 10m, FIG. 22. In such event, the block 11m has two inlet passages 101 and 102 into faces EB and GD of cavity lobes EBF and GDH respectively, these passages being controlled by intake valves 103 and 104 respectively. Two exhaust passages 105 and 106 from faces AE and CG of cavity lobes I-IAE and FCG are also provided, these passages being controlled by exhaust valves 107 and 108 respectively. The valved intake and exhaust may be accomplished through shaft 25m in a manner similar to that shown in FIGS. 11 and 12 or with valves on the housing as in FIG. 13. Two spark plugs 53' and 53" are provided, these being exposed through faces HA and FC of cavity lobes HAE and FCG respectively.

In operation, the relative movement of the rotor and shaft relative to each other and to the housing will be the same as depicted in FIGS. 21A-L. The intake, exhaust, compression and expansion, however, occur at different times and locations within the cavity. The sequence of operations can most easily be explained by considering the cavity portions exposed to face KI of 10 the rotor as it pivots and rotates about its axis in the cavity.

Starting with the position shown in FIG. 22, spark plug 53' is fired and the expanding gases pivot the rotor about its apex K for the power stroke. Next, the rotor pivots about its apex J in cavity corner C so that the rotor apexes I and K move to points B and H respectively in the cavity, shifting the combustion products counterclockwise in the cavity. Pivotal movement of the rotor about its apex I in cavity corner B then forces the just-fired combustion products out through exhaust valve 107. Pivotal movement of the rotor about its apex K in cavity corner A causes fuel to be drawn in through inlet valve 103. Pivotal movement of the rotor about its apex J in cavity corner D then shifts the fuel counterclockwise in the cavity into proximity to spark plug 53". Next, pivotal movement of the rotor about its apex I in corner C compresses the fuel. Spark plug 53" is fired, forcing the rotor to pivot about its apex K in cavity corner B. Next, pivotal movement of the rotor about its apex J in cavity corner A brings rotor apex I into cavity corner D. Pivotal movement of the rotor about its apex I in cavity corner Dv then forces the combustion products out through exhaust valve 108. Next, pivotal movement of rotor apex K in cavity corner C sucks fuel into the cavity through intake valve 104. Pivotal movement of the rotor about its apex in cavity corner B moves the fresh fuel into proximity with spark plug 53. Pivotal movement of the rotor about its apex I in corner A compresses the fuel and the elements are again in the position shown in FIG. 22.

In the above-described sequence of operations, the drive shaft has been driven through three complete revolutions and the rotor has completed two full cycles of firing, exhaust, intake and compression. The other two faces of the rotor cooperate with the cavity walls to go through two identical cycles of intake, fuel shift, compression, expansion, combustion products shift and exhaust, utilizing the same intake and exhaust passage and the same spark plugs; however, the cycles of operation involving the three rotor faces KI, I] and JK are each 120 apart. As a result, with a four-cycle operation, two power strokes will be applied to the drive shaft for each full revolution thereof relative to the housing.

FIG. 19 illustrates the basic engine 10n arranged as a fluid pump. In this case block 1 1n has an intake passage 1 l 1 and an exhaust passage 112 through the peripheral wall into each cavity lobe, the passages being controlled by intake check valves 113 and exhaust valve 114 which allow flow therethrough only in the direction of the arrows indicated on the drawing. An intake manifold 115 connects the source of fluid to be pumped (not shown) to each of the intake check valves. Similarly, an exhaust manifold 116 connects each exhaust check valve 1 14 to a receiver (not shown) to which the fluid is pumped.

Drive shaft 25n is driven by a motor 117 to drive the rotor 35 through its previously described path of movement within the housing cavity. As shown in FIG. 19. counterclockwise pivotal movement of the rotor about its apex K in cavity corner D causes fluid in intake manifold 115 to be drawn into cavity lobe A, and causes fluid to be expelled from cavity lobe C. In the next cycle of movement, when the rotor pivots about its apex J in cavity corner C, fluid will be drawn into cavity lobe D and expelled from cavity lobe B. As the rotor next pivots about its apex I in cavity corner B, the fluid 1 1 previously drawn into cavity lobe B will be expelled therefrom and fluid will be drawn into cavity lobe C.

In operation, each full revolution of drive shaft 25n will draw fluid into each of the four cavity lobes and will pump fluid from each of those lobes, thereby delivering four pump strokes for each shaft revolution.

Although FIG. 19 shows intake and exhaust check valves and manifolds external to block 11n, these passages and valves may be formed in the block, end member and shaft in a manner as shown in FIGS. 11 and 12, if desired.

In addition, as the pump operates, the fluid taken into any given cavity lobe, e.g., the fluid taken into lobe A through the lower right intake valve 113, will be expelled through the exhaust check valve for that lobe, i.e., the lower right exhaust valve 114. As a consequence the pump can be used to pumpa plurality of different fluids therethrough without intermixing the fluids within the pump. Thus, one fluid may be taken into cavity lobe A and pumped therefrom while a different fluid is taken into cavity lobe B and pumped therefrom. In such case, of course, common intake and exhaust manifolds would not be used, but instead separate intake and exhaust conduits would be used for the different fluids involved.

FIG. 20 illustrates diagrammatically an arrangement wherein the engine p is utilized as a flfuid motor, whereby a gas or liquid under pressure may be utilized to drive the drive shaft 25p.

Block 11p is again provided with intake passages 121 into each cavity lobe, the intake passages being connected by conduits 122 to the downstream sides of intake valves 123. Intake manifolds 124 and 125 supply fluid under pressure from a suitable source (not shown) to the upstream side of each intake valve. The valve stems 126 of each intake valve ride against cam 127 mounted on drive shaft 25p so that the intake valves are sequentially opened by cam lobe 128 to allow fluid under pressure to flow into the cavity lobes.

In a similar manner, each cavity lobe has an exhaust passage 131 therefrom, connected by a conduit 132 to the upstream side of one of the four exhaust valves 133. The downstream side of the exhaust valves communicate with an exhaust manifold 134. The valve stems 135 of each exhaust valve ride against cam 136, also mounted on drive shaft 25p so that the exhaust valves are sequentially opened by cam lobe 137 to allow fluid to exhaust from the four cavity lobes. If desired, two lobes can be opened to exhaust at one time. As for example, in FIG. 20, fluid under pressure is being introduced into cavity lobe A to provide the power stroke to shaft 25p, and cavity lobes B and C are open to the exhaust manifold.

In operation, each cavity lobe will be charged sequentially with fluid under pressure to provide four power strokes for each full revolution of the drive shaft 25p.

If desired, fluid under pressure can be delivered to both intake manifolds 124 and 125 for full power, with four power strokes per shaft revolution, with fluid being then delivered to only one of the intake manifolds for cruising or light-load operations, with only two power strokes being imparted to the drive shaft for one shaft revolution.

Also, if desired, instead of using external intake and exhaust conduits and cam-operated intake and exhaust valves as shown in FIG. 20, internal passages, with valved operation thereof can be provided in a manner 12 as shown in FIGS. 12 and 13. In such case, if a dual intake system is desired, comparable to the dual intake manifolds 124 and of FIG. 20, intake into two cavity lobes can be provided utilizing a shaft through the opposite end wall of the housing.

In the various modifications of the invention shown and described herein, shaft bearings, gaskets and other seals, lubricating systems, details of fuel injectors or superchargers, adjustment of spark timing for advance or retard, starter motors and other such accessory units have not been shown. However, such elements are conventional and are to be used when and where necessary to provide the desired results of the engines.

Having thus described our invention, we claim:

1. A rotary engine comprising:

a housing having axially spaced end walls and a peripheral wall interconnecting the end walls to form a four-lobed cavity having an axis and being of constant cross section along said axis, said cavity having four corner edges spaced equidistantly from and equiangularly around said axis, said cavity having two wall surfaces facing and spaced from each corner edge, the wall surfaces being sections of a circular cylinder whose axis is along the corner towards which said wall surfaces face and whose radius is equal to the distance between adjacent corner edges,

a three-lobed rotor disposed in said cavity and having an axis parallel to and offset from the axis of said cavity and being of constant cross-section along the axis thereof, said rotor having three apexes equidistant from each other and equidistant from the axis of said rotor, the distance between apexes being equal to the distance between adjacent cavity corner edges, the rotor having a shape between each pair of apexes generally complementary to the shape of said cavity between adjacent corner edges thereof,

a shaft rotatably journaled in and extending through one of said end walls into said cavity coaxially therewith,

means forming a radially extending slot on one end of said shaft,

a drive stub on said rotor coaxial thereof, said drive stub projecting into said slot and being confined therein for translatory movement radially towards and away from the axis of said shaft as said shaft and housing rotate relative to each other,

means for introducing fluid into selected lobes of said cavity,

means for exhausting fluid from selected lobes of said cavity.

2. A rotary engine as set forth in claim 1 and further including:

a second shaft rotatably journaled in and extending through the other of said end walls into said cavity coaxially therewith,

means forming a radially extending slot on the end of said second shaft,

a second drive stub on said rotor coaxial thereof, said second drive stub projecting into said slot of said second shaft, and

wherein said means for introducing fluid into selected lobes of said cavity includes means forming a passage extending longitudinally through one of said shafts from exteriorly of said housing to interiorly of said housing, and

13 wherein said means for exhausting fluid from selected lobes of said cavity includes means forming a passage extending longitudinally through the other of said shaft from exteriorly of said housing to interiorly of said housing.

3. A rotary engine as set forth in claim 1 wherein said means for introducing fluid into and exhausting fluid from selected lobes of said cavity include means forming inlet and exhaust passages through said peripheral wall from exteriorly of said housing to the lobes of said cavity therewithin.

4. A rotary engine as set forth in claim 1 and further including a frame, means for supporting said housing on and in fixed relationship to said frame, and a power drive connection on said shaft.

5. A rotary engine as set forth in claim 1 and further including a frame, means for supporting said shaft on and in fixed relationship to said frame, and a power drive connection on said housing.

6. A rotary engine as set forth in claim 1 and further including a frame, means for supporting both said housing and said shaft on and for rotational movement relative to said frame and independent power drive connections on'said housing and on said shaft.

7. Apparatus as set forth in claim 1, wherein said means for introducing fluid into selected lobes of said cavity includes means forming an intake passage into each selected cavity lobe and a check valve in each intake passage arranged to allow flow through said intake passages only into said cavity,

wherein said means for exhausting fluid from selected lobes of said cavity includes means forming an exhaust passage from each selected cavity lobe and a check valve in each exhaust passage arranged to allow flow through exhaust passages only from said cavity,

and power drive means for rotating said shaft relative to said housing.

8. Apparatus as set forth in claim 7, wherein an intake passage is formed into each of the four cavity lobes and an exhaust passage is formed from each of the four cavity lobes.

9. Apparatus as set forth in claim 1,

wherein said means for introducing fluid into selected lobes of said cavity includes means forming an intake passage in said peripheral wall opening into each selected cavity lobe, an intake valve in each intake passage and means operated in response to relative rotation of said shaft and housing for intermittently opening and closing said valves in sequence to allow fluid to flow into said selected cavity lobes,

wherein said means for exhausting fluid from selected lobes of said cavity includes means forming an exhaust passage in said peripheral wall opening into each selected cavity lobe, an exhaust valve in each exhaust passage and means operated in response to relative rotation of said shaft and housing for intermittently opening and closing said valves in sequence to allow fluid to flow from said selected cavity lobes,

and means for delivering fluid under pressure to each intake passage upstream of the intake valve therein.

10. Apparatus as set forth in claim 9 wherein an intake passage is formed into each of the four cavity lobes and an exhaust passage is formed from each of the four cavity lobes.

11. A rotary engine as set forth in claim 1 wherein said means for introducing fluid into and said means for exhausting fluid from selected lobes of said cavity each include means forming a passage extending longitudinally through said shaft from exteriorly of said housing to interiorly of said housing and means exteriorly of said housing for connecting said passages through said shaft to fluid inlet and exhaust conduits.

12. A rotary engine as set forth in claim 2 wherein said passages communicate directly with said cavity through the end of said shaft and wherein an end of said rotor wipes across said end of said shaft to open and close said passages.

13. A rotary engine as set forth in claim 11 wherein said passages through said shaft terminate in openings radially of said shaft, and further including means forming a passage from each cavity lobe through said end wall for sequential communication with each of said shaft openings as said shaft rotates in said end wall.

14. A rotary engine as set forth in claim 1 and further including means forming a compression depression in one surface of each rotor lobe and a fuel igniter means in one wall of selected of said cavity lobes.

15. A rotary engine as set forth in claim 14 wherein said means for introducing fluid into and exhausting fluid from selected lobes of said cavity includes means forming separate intake and exhaust passages into and from each of the four cavity lobes and wherein a separate fuel igniter means is provided for each of the four cavity lobes.

16. A rotary engine as set forth in claim 14 and further including a second rotary engine as defined in claim 14, the shaft of said second engine being rotatably journaled in and extending through the other end wall of said first engine into the cavity thereof and coaxial therewith,

means forming a radially extendiing slot on the other end of said shaft of said second engine,

a second drive stub on the rotor of said first engine coaxially therewith, said second drive stub projecting into said last-named slot.

17. Apparatus as set forth in claim 16 wherein the slots on the ends of the shaft of said second engine are radially offset by an odd multiple of approximately 45.

18. Apparatus as set forth in claim 16 and further including a third shaft rotatably journaled in and extending through the other end wall of said second engine into the cavity thereof and coaxially therewith,

means forming a radially extending slot on the end of said third shaft,

a second drive stub on and coaxial to the rotor of said second engine, said last-named drive stub projecting into said slot of said third shaft.

19. Apparatus as set forth in claim 18, wherein said means for introducing fluid into and exhausting fluid from selected lobes of said engines includes means for introducing into said second engine the fluid exhausted from said first engine.

20. Apparatus as set forth in claim 18, wherein said means for introducing fluid into and exhausting fluid from selected lobes of said engines includes:

means forming a passage extending longitudinally through the shaft of the first engine from exteriorly thereof to interiorly thereof for introducing fluid into the cavity lobes of said first engine,

means forming a passage extending longitudinally through the shaft of the second engine from the interior of said first engine to the interior of said sec- 1 5 through said third shaft from exteriorly of said second engme for exhaustmg fluld from the Cav'ty nd engine to interiorly thereof for exhausting fluid from the cavity lobes of said second engine.

lobes of said first engine and introducing such fluid into the cavity lobes of said second engine,

means forming a passage extending longitudinally 

1. A rotary engine comprising: a housing having axially spaced end walls and a peripheral wall interconnecting the end walls to form a four-lobed cavity having an axis and being of constant cross section along said axis, said cavity having four corner edges spaced equidistantly from and equiangularly around said axis, said cavity having two wall surfaces facing and spaced from each corner edge, the wall surfaces being sections of a circular cylinder whose axis is along the corner towards which said wall surfaces face and whose radius is equal to the distance between adjacent corner edges, a three-lobed rotor disposed in said cavity and having an axis parallel to and offset from the axis of said cavity and being of constant cross-section along the axis thereof, said rotor having three apexes equidistant from each other and equidistant from the axis of said rotor, the distance between apexes being equal to the distance between adjacent cavity corner edges, the rotor having a shape between each pair of apexes generally complementary to the shape of said cavity between adjacent corner edges thereof, a shaft rotatably journaled in and extending through one of said end walls into said cavity coaxially therewith, means forming a radially extending slot on one end of said shaft, a drive stub on said rotor coaxial thereof, said drive stub projecting into said slot and being confined therein for translatory movement radially towards and away from the axis of said shaft as said shaft and housing rotate relative to each other, means for introducing fluid into selected lobes of said cavity, means for exhausting fluid from selected lobes of said cavity.
 2. A rotary engine as set forth in claim 1 and further including: a second shaft rotatably journaled in and extending through the other of said end walls into said cavity coaxially therewith, means forming a radially extending slot on the end of said second shaft, a second drive stub on said rotor coaxial thereof, said second drive stub projecting into said slot of said second shaft, and wherein said means for introducing fluid into selected lobes of said cavity includes means forming a passage extending longitudinally through one of said shafts from exteriorly of said housing to interiorly of said housing, and wherein said means for exhausting fluid from selected lobes of said cavity includes means forming a passage extending longitudinally through the other of said shaft from exteriorly of said housing to interiorly of said housing.
 3. A rotary engine as set forth in claim 1 wherein said means for introducing fluid into and exhausting fluid from selected lobes of said cavity include means forming inlet and exhaust passages through said peripheral wall from exteriorly of said housing to the lobes of said cavity therewithin.
 4. A rotary engine as set forth in claim 1 and further including a frame, means for supporting said housing on and in fixed reLationship to said frame, and a power drive connection on said shaft.
 5. A rotary engine as set forth in claim 1 and further including a frame, means for supporting said shaft on and in fixed relationship to said frame, and a power drive connection on said housing.
 6. A rotary engine as set forth in claim 1 and further including a frame, means for supporting both said housing and said shaft on and for rotational movement relative to said frame and independent power drive connections on said housing and on said shaft.
 7. Apparatus as set forth in claim 1, wherein said means for introducing fluid into selected lobes of said cavity includes means forming an intake passage into each selected cavity lobe and a check valve in each intake passage arranged to allow flow through said intake passages only into said cavity, wherein said means for exhausting fluid from selected lobes of said cavity includes means forming an exhaust passage from each selected cavity lobe and a check valve in each exhaust passage arranged to allow flow through exhaust passages only from said cavity, and power drive means for rotating said shaft relative to said housing.
 8. Apparatus as set forth in claim 7, wherein an intake passage is formed into each of the four cavity lobes and an exhaust passage is formed from each of the four cavity lobes.
 9. Apparatus as set forth in claim 1, wherein said means for introducing fluid into selected lobes of said cavity includes means forming an intake passage in said peripheral wall opening into each selected cavity lobe, an intake valve in each intake passage and means operated in response to relative rotation of said shaft and housing for intermittently opening and closing said valves in sequence to allow fluid to flow into said selected cavity lobes, wherein said means for exhausting fluid from selected lobes of said cavity includes means forming an exhaust passage in said peripheral wall opening into each selected cavity lobe, an exhaust valve in each exhaust passage and means operated in response to relative rotation of said shaft and housing for intermittently opening and closing said valves in sequence to allow fluid to flow from said selected cavity lobes, and means for delivering fluid under pressure to each intake passage upstream of the intake valve therein.
 10. Apparatus as set forth in claim 9 wherein an intake passage is formed into each of the four cavity lobes and an exhaust passage is formed from each of the four cavity lobes.
 11. A rotary engine as set forth in claim 1 wherein said means for introducing fluid into and said means for exhausting fluid from selected lobes of said cavity each include means forming a passage extending longitudinally through said shaft from exteriorly of said housing to interiorly of said housing and means exteriorly of said housing for connecting said passages through said shaft to fluid inlet and exhaust conduits.
 12. A rotary engine as set forth in claim 2 wherein said passages communicate directly with said cavity through the end of said shaft and wherein an end of said rotor wipes across said end of said shaft to open and close said passages.
 13. A rotary engine as set forth in claim 11 wherein said passages through said shaft terminate in openings radially of said shaft, and further including means forming a passage from each cavity lobe through said end wall for sequential communication with each of said shaft openings as said shaft rotates in said end wall.
 14. A rotary engine as set forth in claim 1 and further including means forming a compression depression in one surface of each rotor lobe and a fuel igniter means in one wall of selected of said cavity lobes.
 15. A rotary engine as set forth in claim 14 wherein said means for introducing fluid into and exhausting fluid from selected lobes of said cavity includes means forming separate intake and exhaust passages into and from each of the four cavity lobes and wherein a separate fuel igniter means is provided for each of the four cavity lobes.
 16. A rotary engine as set forth in claim 14 and further including a second rotary engine as defined in claim 14, the shaft of said second engine being rotatably journaled in and extending through the other end wall of said first engine into the cavity thereof and coaxial therewith, means forming a radially extendiing slot on the other end of said shaft of said second engine, a second drive stub on the rotor of said first engine coaxially therewith, said second drive stub projecting into said last-named slot.
 17. Apparatus as set forth in claim 16 wherein the slots on the ends of the shaft of said second engine are radially offset by an odd multiple of approximately 45*.
 18. Apparatus as set forth in claim 16 and further including a third shaft rotatably journaled in and extending through the other end wall of said second engine into the cavity thereof and coaxially therewith, means forming a radially extending slot on the end of said third shaft, a second drive stub on and coaxial to the rotor of said second engine, said last-named drive stub projecting into said slot of said third shaft.
 19. Apparatus as set forth in claim 18, wherein said means for introducing fluid into and exhausting fluid from selected lobes of said engines includes means for introducing into said second engine the fluid exhausted from said first engine.
 20. Apparatus as set forth in claim 18, wherein said means for introducing fluid into and exhausting fluid from selected lobes of said engines includes: means forming a passage extending longitudinally through the shaft of the first engine from exteriorly thereof to interiorly thereof for introducing fluid into the cavity lobes of said first engine, means forming a passage extending longitudinally through the shaft of the second engine from the interior of said first engine to the interior of said second engine for exhausting fluid from the cavity lobes of said first engine and introducing such fluid into the cavity lobes of said second engine, means forming a passage extending longitudinally through said third shaft from exteriorly of said second engine to interiorly thereof for exhausting fluid from the cavity lobes of said second engine. 